Full length greenbox

How would you plan a full length greenbox photo session on an event where there will be 2-300 visitors?

Im interested the backdrop and lighting setup solutions for that full length photos and the software solutions too to be able to put them on different backgrounds and print.

Thank you for the adveices in advance!

You mean 'green screen' not 'green box'.

You MUST light a green screen background uniformly in order for the software to detect (and uniformly substitute whatever photographic scene), usually within 0.5EV across the entire area. Odinarily the brightness level should be about one stop under the key light, so as to avoid green spill contamination of the main subject. Have you got a good lighting kit to do that, along with an exposure meter to measure for uniformity of illumination?

Generally you want to distance the subject from the green screen to avoid bounceback contamination of the subjects. And, of course, you want to illuminate the subjects well, independent of green screen lighting.

Lastly, where your background has strongly directional light visible via shadows, etc., you want the subject light to be directionally CONSISTENT!